California Code, Civil Code - CIV § 2981.9

Every conditional sale contract subject to this chapter shall be in writing and, if printed, shall be printed in type no smaller than 6-point, and shall contain in a single document all of the agreements of the buyer and seller with respect to the total cost and the terms of payment for the motor vehicle, including any promissory notes or any other evidences of indebtedness. The conditional sale contract or a purchase order shall be signed by the buyer or his or her authorized representative and by the seller or its authorized representative. An exact copy of the contract or purchase order shall be furnished to the buyer by the seller at the time the buyer and the seller have signed it. No motor vehicle shall be delivered pursuant to a contract subject to this chapter until the seller delivers to the buyer a fully executed copy of the conditional sale contract or purchase order and any vehicle purchase proposal and any credit statement which the seller has required or requested the buyer to sign and which he or she has signed during the contract negotiations. The seller shall not obtain the signature of the buyer to a contract when it contains blank spaces to be filled in after it has been signed.